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When Chevy announced the all-new 2018 Traverse and Buick announced the all-new 2018 Enclave, we assumed that both full-size crossovers were powered by GM’s all-new 3.6L V-6 LGX engine. But after some digging around, we realized that this is not the case. Instead, the 2018 Chevrolet Traverse and Buick Enclave are powered by a version of GM’s 3.6L V-6 LFX engine.

Assigned RPO code LFY, the motor powering the 2018 Traverse and Enclave is assigned RPO code LFY. It is essentially the same LFX engine that was ubiquitously used across many last-generation GM vehicles, but with the auto engine stop/start feature added.

In most vehicles that use a 3.6L V-6, the LFX has been superseded by the LGX — a clean-sheet high-feature V-6 engine family that improved on the LFX in every way, including power, refinement, and efficiency. So, why does it even matter? For a few reasons.

Why It Matters

First, the LFY is only slightly less powerful than the LGX. Second, the LFX does not represent the latest and greatest in GM V-6 engine engineering. Meanwhile, other vehicles that share the C1 platform with the new Traverse and Enclave — specifically the second-generation 2017 GMC Acadia and 2017 Cadillac XT5 — are powered by the LGX motor, not the LFY.

3.6L V-6 LFY vs. 3.6L LGX Comparison

Vehicle

Engine

Generation

Overview / Features

Power hp / kW @ RPM

Torque lb-ft / Nm @ RPM

2018 Chevrolet Traverse

3.6L V-6 LFY

HFV6 Gen 1+

DOHC, SIDI, VVT, Auto Stop/Start

305 / 228 @ 6800

260 / 353 @ 2800

2018 Buick Enclave

3.6L V-6 LFY

HFV6 Gen 1+

DOHC, SIDI, VVT, Auto Stop/Start

305 / 228 @ 6800

260 / 353 @ 2800

2017 GMC Acadia

3.6L V-6 LGX

HFV6 Gen 2

DOHC, SIDI, VVT, Auto Stop/Start

310 / 231.1 @ 6600

271 / 365.9 @ 5000

2017 Cadillac XT5

3.6L V-6 LGX

HFV6 Gen 2

DOHC, SIDI, VVT, Auto Stop/Start

310 / 231.1 @ 6600

271 / 365.9 @ 5000

Table Legend

Terminology

DOHC – Dual Overhead Cam engine configuration

SIDI – Spark Ignition Direct Injection

VVT – Variable Valve Timing

HFV6 – High Feature V-6 engine, GM’s internal designation for modern V-6 engines with SIDE and VVT

The GM Authority Take

In all, GM’s choice not to include the latest 3.6L V-6 LGX engine in the 2018 Traverse and Enclave is interesting. Chances are that the decision was made to maximize per-vehicle profit, since the LFX motor delivers similar performance (at least on paper) at the LGX, while likely being much less expensive to produce, as it has been in production at the GM St. Catharines powertrain plant in Ontario, Canada for years. As such, its tooling has already been paid off.

Where a difference between the new LGX and last-gen LFX/LFY can be noticed is not on paper, but rather in refinement and noise, vibration, and harshness (NVH) levels, areas that are (unfortunately) unappreciated by the average car buyer, as they are not easy to quanitfy. In our opinion, differentiating between the GM’s new and old six-bangers takes a skilled driver on the level of an enthusiast — something that most Traverse and Enclave buyers are (likely) not. Therefore, they probably will never notice nor appreciate an awesome engine like the LGX, especially given that it likely costs GM more to produce it compared to the LFX/LFY.

Some Parting Trivia

Interestingly, GM has a history of stuffing last-generation engines into its family haulers. The first-generation Traverse, Enclave, and Acadia were introduced with the LLT first-generation HFV6 engine. When the automaker introduced the LFX as an update to the LLT, the trio never got it, instead soldering on with the LLT for their entire lifecycle.

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53 Comments

This is not good. The LGX is designed as a stop/start engine, not the previous engine. This will not be great for reliability. GM can afford it for Colorado, but not Traverse/Enclave?? This is an old gm thing to do. Leave the old v6 in the past or give it us without stop/start nonsense.

Replying to your comment for better visibility (mine is about 15 threads down as of now); and you are right to bring up the start-stop, LFX/LLT/LY7’s were not designed with that in mind, one clue to look a little closer:

NOT TRUE: While they may use engine code LFY, they are part of the 2nd gen LGX family – see the specs listed on Chevy’s Media site. The bore/stroke and displacement all match the LGX family, not the LFX/LLT/LY7. The power and torque specs are listed as estimates, likely to be uprated at introduction. PLEASE CORRECT THE ARTICLE!

The only reason I could see is that the peak torque moves to an even higher RPM with the LGX. That is not a good thing for drive-ability on a heavy crossover. If anything, these engines in this application need more low end torque, not more peak HP. It bugs me every time I drive my wife’s Traverse.

Where I have an issue is utilizing this “old” engine in a vehicle as the Avenir, that will be marketed based upon luxury, sophistication, and advanced technology. How can they even consider utilizing an engine that is very similar to one introduced in 2008?

As I’ve stated before, cannot understand how they could be utilizing this engine in a vehicle that will probably be in the $55K to $65K range. Acceleration figures by Buick are 7.2–7.5 to 60. This is not much better than a Cruze! Any knowledgeable buyer that researchs the product will likely move on to one of the competitors.

True. But that doesn’t translate to sales for Lincoln as Enclave doesn’t outsell the Lincoln for the whole 9 yards. Avenir could be at most 60k but again Cadillac will have its own stretched version of the XT5 and competes with the MB and Audi

Traverse and Enclave are equivalent in size to the Mercedes GLE.
My local MB dealer has 7 2017 GLEs available. They range in price from $61k – $80k.
My local Chevy dealer has 10 2017 Traverse’s in stock. They range in price from $31k – $46k.
The local Buick dealer has 50 Enclaves in stock. They range in price from $38k – $47k.
Let’s add 20% to the Buick for the Avenir package. That tops the Buick out at $56k.
Buyers do NOT cross shop the German luxury brands with Buick and Chevy. It just doesn’t happen. I never considered a Buick before purchasing either Benz I have owned. I looked at BMW, Audi and Cadillac.
The Mercedes GLC (Equinox size) is $46k – $68k. Perhaps the guy looking at the base GLC may consider moving to a larger, loaded Enclave but I genuinely doubt it.

I’ve had the opportunity to drive the new Traverse in its pre production form back to back with an Ecoboost explorer. Trust me when I say this, there is no comparison. The V6 in the Traverse will get up and go quite a bit better than the Ecoboost in the Ford/Lincoln.

I thought the Canyon had the LGZ, which is an LGX tuned with more torque at a lower RPM (275 @ 4000). Given the truck specific tuning for low end torque and lower 3:42 rear gearing, I’m not sure that it can aptly be compared to the acceleration characteristics of the CUV’s in the article.

Personally, I find the high revving engines maddening when trying to merge with traffic, but if the new transmissions are calibrated correctly with quicker shifting response to throttle input, then that should help a great deal.

Shocking move by GM to say the least. I honestly have no idea why you would be able to get the Acadia with the new 3.6 but not the more expensive Buick Enclave. GM still makes some head scratching decisions. Baffling to say the least. I thought GM had turned the page on small things like this. Guess not.
If they produce these vehicles for one year with the older 3.6 and then the following year they place the new engine in them, i would be one very upset customer had I purchased the vehicle a couple month earlier.

LFY engine has Start stop system. Most likely these new engines LGX weren’t up too full production yet, before these new crssovers came out. These new 9 speed automatic’s are on these new enclave and new Chevrolet transverse ,

Yes, I was confused when the 2018 Traverse/Enclave was introduced. I am still a bit confused-will the V6 in the Traverse/Enclave be the same as in the 2007-2017 GMC Acadia/Enclave/Traverse?
If so mine never, never gets over 21 unless holding at 55 mph and perhaps 13 around town (which I never use it for).
Two more questions:
1. Does anyone know if the silly Stop/Start feature can be disabled? The thought of a drunk ramming me at a light while the engine/transmission is stumbling to get moving again
2. Since GM is using a much older engine, can I assume they will NOT have AFM on it (ability to run 4 cylinders rather than 6) which has been a huge failure on GM pickups the last few years I gather. It they are not using AFM that is a HUGE plus for the old motor!!

1: You can disable stop/start but you have to do it every time you start the vehicle.
2: By 2014 GM had cylinder deactivation in the Silverado figured out. My 2012 was suffering from the oil consumption issues associated with AFM. My 2014 had no problems.

Stupid argument against start/stop, While annoying and a “feature” I hope you can disable (even if that means having to do it everytime), I have never had and vehicle equipped with start/stop ‘stumble to get moving again’. And even so in your scenario the drunk was probably going to hit you one way or another. Hard to imagine that “stumbling” while restarting would make any difference.

Stupid argument against start/stop, While annoying and a “feature” I hope you can disable (even if that means having to do it everytime), I have never had any vehicle equipped with start/stop ‘stumble to get moving again’. And even so in your scenario the drunk was probably going to hit you one way or another. Hard to imagine that “stumbling” while restarting would make any difference.

I agree that the idea of a drunk hitting you and being doomed by start stop is just total foolishness.

I am not a fan of start stop and would love to have the choice of shutting it off. But having driven one again this week the system is seemless. The only aspect I can complain about is a slight shake due to the 4 cylinder start up.

As for the AFM I drive one daily and you would be had presses to make the call as to how many cylinders are in or out.

The durability at this point is not an issue.

If you have a beef with it and just honest and say you don’t like it, don’t just make crap up.

Well, the REAL Bob Lutz, the most gifted “car guy” in the last 25 years or so; ex Vice Chairman of GM; author of several books detailing the GM era of 2000-2010 when nightmares like the ORIGINAL GMC Acadia, Buick Enclave, Saturn Outlook, etc were turned into the biggest lemons since the OLDS/Pontiac Diesels, would not call concern over superfluous GM application of new technology that could be fatal as STUPID.
As he noted in “Car Guys vs. Bean Counters” and “Icons and Idiots”, GM lost control of the whole rollout of the first generation of SUVs just now being replaced with unfixable leaking sunroofs that led to major electrical failures; camshafts too short; timing chain failures, major transmission failures; necessary replacement of critical steering components, and a long list of failures for design/manufacture to live up to Marketing hype.
My concern is based on my experience of vehicles of that period and living with how really stupid “bright ideas” can sometimes be and the buyer’s need to objectively evaluate new technology, not just be naïve and accepting without proof of merit and execution. GM (and Ford for that matter) can do a great job when they set their minds to it, but proof is in the quality of the execution, and only time will tell if Stop/Start on cars will be any better than on a crude mountain golf cart.

NOT TRUE: While they may use engine code LFY, they are part of the 2nd gen LGX family – see the specs listed on Chevy’s Media site. The bore/stroke and displacement all match the LGX family, not the LFX/LLT/LY7. The power and torque specs are listed as estimates, likely to be uprated at introduction. PLEASE CORRECT THE ARTICLE!

Ummm, everyone, the 3.6L Engine in the 2017 GMC Acadia does not have Stop/Start technology. The 2.5L 4 Cylinder does, but the 6 does not get that feature. It’s also paired to a 6-speed Automatic unlike the XT5 and the upcoming Traverse/Enclave that get more gears.

People are complaining about what engine is going in a large cuv and I ask why? Both engines that are referenced are very close in terms of power. New vs old is something 99 % of the buyers won’t care or won’t even be aware of. AND lastly taking about engines on these types of cars not having enough power is a joke. These types of vehicles are used my soccer mom’s and grocery getters and pull a small trailer. The focus should be on what’s going on inside this car not what’s under the hood!

Weird but so GM. They have a reputation for doing this sort of thing. There have been so many complaints regarding stop/start that many folks have omitted buying a car so equipped. So what does GM do? Shove it down everybody’s throat and worse not including a proper defeat switch like Jeep and most every other manufacturer does.

And why do we need 4 variations of the 3.6 engine with 20 differing states of tune? If it were up to me the Chevy would have the 305/275 torque version of the LGX and the more costly Buick would have the 335/285 rated higher output motor as used in the Camaro and certain Cadillac sedans. You should be getting more than woodgrain, chrome, fancier interior and a different badge for 10 grand extra!

As other stated, it’s a volume issue. There are engine production lines that need to be converted and it takes time. Also, if there were a recall or supplier issue on the all-new LGX, GM would be exposed with no engines at all.

You’ve got to be kidding me. I was strongly considering the new 2018 Enclave to replace my 2009 Enclave, but not if it has a non-defeatable “stop/start”. I do not want the stupid “start/stop” feature. I do not want my engine shutting off at a stop light. People who pay $50,000 or more for a vehicle do not care about the minuscule amount of gas that would be saved by this feature.

That’s not a serious option for me, lol. I have wound the engine up pretty good a few times when I forgot that I had mine in that mode.

I did this afternoon drive a 2017 Acadia Denali. Not bad, but I don’t think it has the ride or road isolation of the Enclave, even my 2009, possibly because the Acadia Denali wore lower profile tires than the 2017 Enclave Premier parked next to it. I think the Acadia tires were 235 ratio, while the Enclave tires were 255, which means a taller sidewall and more flex.

Also, things are just a bit less spacious in the Acadia. Even though it is supposed to be 700 pounds lighter, it did not seem to have noticeably “snappier” acceleration than mine. And I do think, with its new 9-speed transmission the 2018 Enclave might actually have lower gearing in the lower gears and end up being peppier from 0 to 40mph or so. I’ll definitely wait until the new Enclave is released and check it out.

It is disappointing that about a month after this article appeared, a long Google search for specific GM details on the new stop/start system reveals no Engineering facts, only GM marketing hype to support the forced inclusion of this “feature”.
If it indeed can be disabled, manually or otherwise, great. However no GM discussion appears anywhere to support this as a production fact. Yes, I do hate the concept this type of potentially riskier addition being forced down the GM customer’s throat for little or no gain (again there is not one shred of GM Engineering data to support the inclusion of Stop/Start as a fuel saving technique. By the XXXX increase in starter cycle over the life of the vehicle means a huge increase in vehicle maintenance costs way, way less than any few drops of fuel saved).
As too with the AFM, if they have finally got it working without GM’s previous generations’ oil consumption and maintenance costs, swell. However GM needs to talk in public about what is better technically with the new AFM system than their previous generation of failures, and quit letting the marketing department do the engineering departments’ explaining.

Thanks for doing the Google search. IMO, there is no way enough fuel can be saved to offset the cost of a starter replacement, and my suspicion is that this start/stop stuff is mostly a way to appear more PC and appeal to people worried about climate change. I was initially just aggravated with not being able to defeat it, but I didn’t even think about how many additional times the starter would be engaged.

I take it your not too bright! In some ways maybe your just stuck in your old ways but saying would sound like a compliment. This is something that I don’t think you deserve.

You don’t like start stop technology? Let me guess you didn’t like disc brakes, A/C, P/S, Fuel injection, MRC, I could go on but I think people get the point!,

Just because you don’t like it doesn’t mean GM shouldn’t produce them. GM is forcing it down your throat, GM is forced to do this in order to meet regulations in the future.

This type of technology is here to stay so you and your not on my lawn type of people better get use to it because every car built in the near future will have some sort of fuel saving technology.

So it’s time for you to put on your big boy pants and stop acting like a two year old! Be a adult and realize that the world is changing and you are going to be apart of it weather you like it or not!

GM doesn’t make cars for you and you alone, this makes you seem very argonaut. That cars have to be built to your specifications or the car is a failure. Who are you to decide what the rest of the world gets?

These fuel saving systems that GM uses from start stop, DoD, VVT, hybrid ect ect ect! I don’t need a report to know that these systems that are used save fuel a little bit at a time. I should know I own one of them. Works great!

This seems to me like more of a control issue on your part then anything else. Which is not a very good reason to dislike it!